The NRA have provided no support in terms of risk assessment to help clubs using MoD ranges. I am in the North East of England and a club member developed a risk assessment which both the MoD and Landmarc have accepted when a bid/ rasp is submitted and is being used by the clubs up here.
I suggest you knock up a rask assessment and run it past your local range management. I know the NRA have a copy of our ones.